JPH0320048B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a novel rare earth magnet material, which is based on FeBR and contains an additive element M, in particular
This article relates to a method for manufacturing high-performance permanent magnet materials that do not necessarily require rare rare earth metals such as Sm, and whose main components are light rare earths such as Nd and Pr, which are abundant in resources and have few uses, and Fe. Permanent magnetic materials are one of the extremely important electrical and electronic materials used in a wide range of fields, from various household appliances to peripheral terminal equipment for large computers. In recent years, with the demand for smaller and more efficient electrical equipment, permanent magnet materials are required to have even higher performance. Furthermore, there is a need for magnetic materials with high coercive force in many practical applications where extremely large reverse magnetic fields are applied, such as magnetic couplings for motor generators. Representative permanent magnet materials currently in use are alnico, hard ferrite, and rare earth cobalt magnet materials. A recent permanent magnet material that satisfies high magnetic properties is a rare earth cobalt magnet material. However, rare earth cobalt magnet materials require Sm, which is a scarce resource, and its supply is unstable.
It is very expensive because it uses a large amount of Co. In order for rare earth magnet materials to be used in large quantities in a wide range of fields, it is necessary to use light rare earth metals, which are found in large amounts in ores as rare earth metals, as the main component, without containing large amounts of expensive cobalt. is necessary. As an attempt to develop such a permanent magnet material, an RFe ₂ compound (where R is at least one rare earth metal) has been proposed. Clark (AE
Clark) is an amorphous material obtained by sputtering.
We found that TbFe ₂ has an energy product of 29.5MGOe at 4.2〓, and when it is heat-treated at 300 to 500℃, it exhibits a coercive force of 3.4KOe and a maximum energy product of 7MGOe at room temperature. A similar study was conducted on SmFe ₂ , and it was reported that SmFe 2 showed 9.2 MGOe at 77〓. However, all of these materials are thin films created by sputtering and are not magnetic materials that can be used in general speakers or motors. Also
Ribbon made by ultra-quenching PrFe alloy
It has been reported that it exhibits a high coercive force of 2.8KOe.
Furthermore, Kuhn et al. found that when an amorphous ribbon obtained by ultra-quenching (Fe.B) _0.9 Tb _0.05 La _0.05 was annealed at 627°C, the coercive force reached as high as 9KOe (Br was 5KG). However, in this case, the maximum energy product is low because the magnetization curve has poor squareness (NCKoon
Appl. Phys. Lett. 39(10) 1981, pp. 840-842). Also, L. Kabacoff et al. (Fe, B) _1-
It has been reported that ribbons made _{by ultra} -quenching with a composition of X Pr These ultra-quenched ribbons or thin films produced by sputtering are not practical permanent magnet materials that can be used as such, and practical permanent magnet materials cannot be obtained from these ribbons or thin films. That is, it is not possible to obtain a bulk permanent magnet material having arbitrary shapes and dimensions from the FeBR-based ribbons or RFe-based thin films that have been proposed so far. Also reported so far
The magnetization curve of FeBr-based ribbons has poor squareness and is not considered a practical permanent magnet material that can compete with conventionally used magnet materials. Furthermore, ribbons produced by ultra-quench cooling and thin films produced by sputtering are essentially isotropic, and it has been virtually impossible to obtain practical permanent magnet materials with magnetic anisotropy from them. The purpose of the present invention is to eliminate the drawbacks of conventional methods, eliminate the need to use rare earths such as Sm, and
The basic objective is to obtain a new permanent magnet material that does not contain many problematic components such as Co. Furthermore, the present invention has good magnetic properties at room temperature, can be formed into any shape and practical size, has a highly square magnetization curve, and can effectively use light rare earth elements, which are abundant in resources. It is an object of the present invention to provide a manufacturing method for easily obtaining a permanent magnet material. The present inventors have previously invented an FeBR-based permanent magnet material that does not necessarily require the use of Sm or Co (Japanese Patent Application No. 145072/1982). This FeBR-based permanent magnet material is
It is based on a new compound different from the conventionally known RCo ₅ and R ₂ Co ₁₇ compounds, and in particular boron (B) is used as an amorphous promoting element in the production of amorphous alloys or in powder metallurgy. It is not added as a sintering promoting element, but is an essential constituent element of the R-Fe-B compound that is magnetically stable and has a high magnetic anisotropy constant, which constitutes the substantial content of this FeBR-based permanent magnet material. (In addition, the above
It was also revealed that magnetically anisotropic sintered permanent magnets can be obtained by forming an appropriate microstructure based on FeBR-based permanent magnet materials). Furthermore, such a FeBR-based permanent magnet material can be manufactured by molding an alloy powder (composition) with a predetermined composition and an average particle size of 0.3 to 80 μm, and sintering it at 900 to 1200°C in a non-oxidizing atmosphere. He also invented the invention and filed a separate application (Patent Application 1988-88372). In order to achieve the above object, the present inventors further conducted intensive research on a method for manufacturing a crystalline permanent magnet material based on such FeBR ternary compound.
Based on the FeBR system, a part of Fe is replaced with Co, and an alloy powder of a certain composition range of the FeCoBRM system containing additive elements M (V, Nb, Ta, Mo, W, Cr, Al) is molded and sintered. The present inventors have discovered that a permanent magnet material with extremely excellent magnetic properties, especially coercive force and squareness, can be obtained by further heat-treating the permanent magnet material, leading to the present invention. That is, according to the present invention, 8 to 30% in atomic percentage
R of
is V9.5% or less, Nb12.5% or less, Ta10.5% or less, Mo9.5% or less, W9.5% or less, Cr8.5% or less, and Al9.5% or less, and contains two or more types. (If M is included, the total amount of M is less than a predetermined percentage of the maximum value of each of the M elements contained), and a portion of Fe is 50% of the total composition of the FeBRM system composition in which the remainder is substantially Fe. % or less Co
(excluding 0%) and has a FeCoBRM system composition and is sintered at 900 to 1200℃.
The above object can be achieved by a method for producing a FeCoBRM permanent magnet material, which is characterized in that heat treatment is carried out at a temperature of not less than 0.degree. C. and not more than the sintering temperature. By heat treatment, a significant increase in coercive force can be obtained for a sintered body of the same composition without deteriorating other magnetic properties. This point is extremely significant when compared with the fact that, for example, an increase in coercive force due to an increase in the rare earth element R results in a decrease in residual magnetization (see Japanese Patent Application No. 145072/1982). The presence of a predetermined amount of M further enhances the effect of increasing the coercive force by this heat treatment, and the presence of Co realizes a sufficiently high Kurie point for practical use. In addition, this FeCoBRM-based composition further contains one or more of the elements Similar post-sintering heat treatment effects can be achieved for FeCoBRM-based compositions. In this case, it is preferable to obtain such a sintered body by molding an alloy powder composition having a predetermined composition and an average particle size of 0.3 to 80 μm, particularly by sintering it in a non-oxidizing atmosphere, as in the prior application. The permanent magnet material thus obtained exhibits particularly excellent magnetic properties as a magnetically anisotropic permanent magnet material. The manufacturing method of the present invention is unique in that it can produce a magnetically anisotropic permanent magnet material, unlike the FeBR-based amorphous ribbon produced by the conventional method, but it can also produce an isotropic material. A better product can be obtained. Hereinafter, the case of manufacturing a magnetically anisotropic permanent magnet material will first be explained. In the method for producing a permanent magnet material of the present invention, FeBR
In alloy powder compositions for magnets, the temperature characteristics of the magnet material are improved by partially replacing Fe with Co, but in addition, light rare earths such as Nd and Pr, which are abundant in resources, are used as rare earth elements R. This material exhibits high magnetic properties. Generally, when Co is added to an Fe alloy, the Curie point Tc may rise or fall depending on the amount added, and it is generally difficult to predict the effect of the addition. In the present invention, it has been revealed that as a result of replacing Fe with Co, Tc gradually increases as the amount of Co substitution increases. Moreover, a similar tendency is confirmed regardless of the type of R in the magnet material composition. Even a small amount of Co substitution is effective in increasing Tc, and depending on the amount of Co substitution, an alloy with any Tc of about 310 to about 750°C can be obtained, but the amount of Co is 50% (hereinafter % is the atomic percentage in the alloy). ) The following are sufficient effects. B should be 2% or more to satisfy the coercive force of 1 kOe or more, and the residual magnetic flux density Br of hard ferrite should be approximately
In order to achieve 4kG or more, it must be 28% or less. The rare earth element R is required to be 8% or more in order to obtain a coercive force of 1 kOe or more, and is set to 30% or less because it is easily flammable, difficult to handle and manufacture industrially, and is expensive. As B, pure boron or haferoboron can be used, and a material containing Al, Si, C, etc. as an impurity can be used. As R, a light rare earth element which is abundant in resources can be used, and Sm is not necessarily required or Sm does not need to be the main component, so the raw material is inexpensive and extremely useful. The permanent magnet material obtained by the present invention is advantageous in terms of resources and cost compared to conventional RCo magnet materials, and it can also provide better magnetic properties. The rare earth element R used in the present invention is a rare earth element containing Y and including light rare earths and heavy rare earths, and one or more of them is used. That is, as this R, Nd, Pr, La, Ce,
Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm,
Yb, Lu and Y are included. As R, a light rare earth element is sufficient, and Nd and Pr are particularly preferred. In addition, it is usually sufficient to have one type of R, but in practice, a mixture of two or more types (Mitsushimetal, dididim, etc.) can be used for reasons such as convenience of availability.
La, Ce, Pm, Sm, Eu, Gd, Er, Tm, Yb,
Lu, Y are other R (Nd, Pr, Dy, Ho, Tb), especially
Can be used as a mixture with Nd and Pr.
Note that R does not need to be a pure rare earth element, and may contain impurities that are unavoidable in manufacturing (other rare earth elements, Ca, Mg, Fe, Ti, C, O, etc.) within the industrially available range. I can do it. In the permanent magnet material produced according to the present invention, the additive element M has the effect of increasing the coercive force. Increasing the coercive force increases the stability of the magnet and expands its applications. However, as M increases
Br decreases, and therefore the maximum energy product (BH) max decreases. Recently, there have been many applications that require a high coercive force Hc even if the (BH)max is a little lower, so alloys containing M are very useful, but (BH)max is useful in the range of 4MGOe or more. be. In order to clarify the effect of each addition of the additive element M on Br, the amount added was varied.
Measuring the change in Br, the hard ferrite's Br is approximately 4KG.
The range is equal to or greater than. In addition, considering the range equivalent to or higher than the (BH) max of hard ferrite of approximately 4 MGOe, the upper limit of the amount of M added is V9.5%, Mb12.5%,
Ta10.5%, Mo9.5%, W9.5%, Cr8.5%, Al9.5%
It is. M does not contain 0%, and one type or two or more types can be added. When two or more kinds of additive elements are contained, the average value of the characteristics of each additive element is generally indicated, and the content of each element is within the range of the above percentages, and the total amount is not more than the maximum value of the percentages for each element. When the FeCoBRM system composition is within the above range, the maximum energy product (BH) max is equal to or greater than that of a hard aerite magnet (~4MGOe).
In addition, light rare earth elements, especially Nd and Pr, contain 50% or more of the total R, and 11 to 24% of R, 3 to 27% of B,
Co50% or less (excluding Co00%), additive element M
V8.0% or less, Nb10.5% or less, Ta9.5% or less,
Mo7.5% or less, W7.5% or less, Cr6.5% or less, and
When Al is 7.5% or less, the total amount of M is no more than the atomic percentage of the maximum value of each element of M contained, and the remainder is substantially in the composition range of Fe,
(BH)max is in a preferable range of 7MGOe or more. Furthermore, the most preferable range is light rare earth elements, especially
Contains Nd, Pr in 50% or more of the total R, and 12 to 20
% R, 4-24% B, Co 50% or less (however, Co 0%
), additive elements M are V6.5% or less, Nb8.5% or less, Ta8.5% or less, Mo5.5% or less, W5.5% or less,
Cr4.5% or less and Al5.5% or less, the total amount of M is less than the atomic percentage of the maximum value of each element of M contained, and the remainder is substantially in the composition range of Fe, (BH)max is sufficiently possible to exceed 10MGOe, and the highest maximum energy product is
Reaching 33MGOe or more. Moreover, Fe-Co- of the present invention
For B-R-M alloys, the temperature coefficient (α) of residual magnetic flux density (Br) is α≦0.1%/°C when Co is 5%% or more.
Fe-B has good temperature characteristics and does not contain Co.
Not only does it have better temperature characteristics than the -R alloy, but the addition of Co improves the squareness of the demagnetization curve, leading to an improvement in the maximum energy product. Below 25% Co, other magnetic properties (especially the energy product) are not substantially adversely affected. Co
When exceeds 25%, (BH)max decreases. In addition, since Co has higher corrosion resistance than Fe,
Corrosion resistance can be imparted to the BR alloy by adding Co. Permanent magnet materials made of FeCoBRM-based sintered bodies manufactured by the present invention include Fe, Co, B, R, M
It is also possible to contain small amounts of Cu, C, S, and P (Cu3.5% or less, S2.0% or less, C4.0% or less,
P3.5% or less (however, the total amount is less than the maximum value of each element), improving manufacturability and lowering prices. Furthermore, the inclusion of Ca, Mg, O, and Si is also allowed, especially
Ca, Mg each 4.0% or less, Si 5% or less (the total amount is 5% or less)
% or less) is practically preferred. Even with the inclusion of these elements, it is still comparable to hard ferrite.
It is more than Br (about 4kG) and is useful. Cu, P
may be mixed in from cheap raw materials, C may be mixed in from organic molding aids, and S may be mixed in during the manufacturing process. Note that in the state of alloy powder, adsorbed components (moisture, oxygen, etc.) from the air during processing are likely to be included, but these can be removed during sintering. However, care should be taken in processing and storage as necessary. In addition, the present invention is practical in that it can tolerate the presence of impurities that are inevitable in industrial production. The manufacturing method of the present invention will be further explained below regarding the case of manufacturing a magnetically anisotropic permanent magnet material. First, an alloy powder having the aforementioned FeCoBRM composition is obtained as a starting material. This may be obtained by crushing an alloy ingot obtained by ordinary alloy melting and casting, classification, blending, etc., or it may be obtained by a reduction method from an oxide using a reducing agent such as Ca. It is preferable to use FeCoBRM alloy powder having an average particle size of 0.3 to 80 μm. If the average particle size exceeds 80 μm, excellent magnetic properties cannot be obtained. If the average particle size is less than 0.3 μm, during pulverization or the subsequent manufacturing process,
The oxidation of the powder becomes significant, and the density after sintering does not increase, resulting in poor magnetic properties. Average particle size 40~80μm
In the range of , the coercive force among the magnetic characteristics is somewhat low. In order to obtain excellent magnetic properties, the average particle size of the alloy powder is most preferably 1.0 to 2.0 μm. The pulverization may be carried out by a conventional method, and may be either dry pulverization carried out in an inert gas atmosphere or wet pulverization carried out in an organic solvent. When carrying out in a wet manner, alcohol-based solvents, hexane, trichloroethane, trichloroethylene, xylene, toluene, fluorine-based solvents, paraffin-based solvents, etc. can be used. Next, the alloy powder is shaped. The molding can be carried out in the same manner as the usual powder metallurgy method, preferably pressure molding, and in order to obtain anisotropy, pressing in a magnetic field. For example, alloy powder is 0.5 kOe or more in a magnetic field of 5 kOe or more.
A molded body is formed by applying a pressure of ~3.0Ton/cm ² . This pressure molding in a magnetic field can be performed either by molding the powder as it is or by molding it in an organic solvent such as acetone or toluene. Next, this molded body is sintered at a predetermined temperature (900 to 1200°C) in a reducing or non-oxidizing atmosphere.
For example, this compact is sintered for 0.5 to 4 hours at a temperature range of 900 to 1200°C in a vacuum of 10 ^-2 Torr or less or in an inert gas or reducing gas atmosphere of 1 to 760 Torr and a purity of 99.9% or more. . If the sintering temperature is lower than 900°C, sufficient sintered density and high residual magnetic flux density cannot be obtained. Moreover, above 1200°C, the sintered body is deformed and the orientation of crystal grains is disrupted, resulting in a decrease in residual magnetic flux density and a decrease in the squareness of the demagnetization curve. Further, the sintering time may be 5 minutes or more, but if it is too long, there will be a problem in mass productivity, so in consideration of the reproducibility of the magnetic properties, a sintering time of 0.5 to 4 hours is desirable.
Note that the sintering process is considered to be a heating process in which the density increases as the sintering progresses and reaches a sufficient density. The sintering atmosphere is a non-oxidizing atmosphere, such as a high vacuum or an inert gas or reducing gas atmosphere, since R, which is a component in this alloy, is extremely susceptible to oxidation at high temperatures. The higher the purity of the sexual gas, the better. When using an inert gas, it is also possible to carry out the sintering in a reduced pressure atmosphere of 1 to less than 760 Torr as a method of obtaining high sintering density. The temperature increase rate during sintering is not particularly specified, but in the case of the wet press method, in order to remove the organic solvent, the temperature is increased at a rate of 40℃/min or less, or the temperature is increased from 200℃ to 200℃ during the temperature increase. It is desirable to remove the solvent by holding it in a temperature range of 800°C for 0.5 hours or more. After sintering, the cooling rate to room temperature is preferably 20°C/min or more to reduce product variation.
In order to improve the magnetic properties through subsequent heat treatment (also called aging treatment), the cooling rate must be 100℃/min.
The above is desirable (however, it is also possible to start the heat treatment process immediately after sintering). The aging treatment is carried out in a vacuum, inert gas, or reducing gas atmosphere at a temperature range from 350°C to below the sintering temperature for about 5 minutes to 40 hours. The aging treatment atmosphere should be a vacuum of 10 ^-3 Torr or less, or an inert gas or reducing gas atmosphere, since R, the main component in the alloy, reacts rapidly with oxygen or moisture at high temperatures. A purity of 99.9% or higher is desirable. In the present invention, the optimum sintering temperature of the alloy varies depending on the composition, and the aging treatment must be performed at a temperature below each sintering temperature of the magnet material obtained in the present invention. for example
68Fe10Co8B12Nd2W alloy,
For 58Fe20Co5B16Nd1Al alloy, the upper limit temperature for aging treatment is 920℃ and 1030℃, respectively. In general, the upper limit aging temperature can be increased as the composition is richer in Fe, less B, or less R. However, if the aging treatment temperature is too high, the crystal grains of the alloy will grow excessively in the manufacturing method of the present invention, leading to a decrease in magnetic properties, especially coercive force, and the optimum aging treatment time will be extremely short, making it difficult to control manufacturing conditions. Therefore, it is not practical. Further, if the temperature is lower than 350°C, the aging treatment time will take an extremely long time, which is impractical, and the squareness of the demagnetization curve will deteriorate, making it impossible to obtain an excellent permanent magnet. In order to practically obtain excellent magnetic properties without causing excessive growth of crystal grains in the permanent magnet material obtained by the present invention, the aging treatment temperature must be 450°C to 800°C.
°C is most desirable. The aging treatment is performed for 5 minutes to 40 hours, but if the aging treatment time is less than 5 minutes, the effect of the aging treatment will hardly be apparent, and the obtained magnet properties will vary widely. On the other hand, if the aging treatment exceeds 40 hours, it is difficult to say that it is practical because it takes too long for industrial purposes. In order to practically obtain excellent magnetic properties with good reproducibility, the aging treatment time is preferably 30 minutes to 8 hours. In addition, in the manufacturing method of the present invention, multi-stage aging treatment of two or more stages is also effective as a method for aging the magnetic alloy. For example, 68Fe-10Co-7B-
For 13Nd−1Mo−1Nb alloy, the first stage is 820℃~
After performing the first stage aging treatment in the temperature range of 920℃ for 30 minutes to 6 hours, the second stage and subsequent stages are subjected to one or more stages of aging treatment in the temperature range of 400 to 750℃ for 2 hours to 30 hours. Excellent magnetic properties with high magnetic flux density, coercive force, and squareness of the demagnetization curve can be obtained. In particular, the second and subsequent aging treatments are effective in significantly improving coercive force. In addition, as another method of aging treatment, instead of multi-stage aging treatment,
Even if the temperature range of 800℃ is cooled at a constant cooling rate using air cooling, water cooling, etc., the same magnetic characteristics can be obtained, but the cooling rate in that case is 0.2℃/
It is necessary that the temperature is from min to 20°C/sec. Note that the same magnetic characteristics can be obtained even if these aging treatments are performed as is after sintering, or if the temperature is raised again after cooling to room temperature after sintering. Further, the manufacturing method of the present invention can be applied not only to the manufacturing of magnetically anisotropic permanent magnet materials but also to the manufacturing of isotropic permanent magnet materials. In addition, in the method for producing an isotropic permanent magnet material, the alloy powder is molded without being placed in a magnetic field, and other steps can be used as is. For isotropic case, R10~25%, B3~23%,
In a composition consisting of 50% or less Co, a certain % M, the balance Fe and unavoidable impurities, (BH)
You can get more than max2MGOe. Isotropic magnet materials originally have low magnetic properties, 1/4 to 1/6 of the magnetic properties of anisotropic magnet materials, but according to the present invention, they are nevertheless extremely useful as isotropic materials. High characteristics can be obtained. Even in the case of isotropy, as the amount of R increases, iHc
increases, but Br decreases after reaching its maximum value.
Thus, the amount of R that satisfies (BH)max2MGOe or more is 10% or more and 25% or less. Also, as the amount of B increases, iHc increases, but Br
decreases after reaching its maximum value. Thus (BH)
Must be in the range of B3-23% to get max2MGOe or higher. Preferably, light rare earths are the main components of R, especially Nd, Pr (at least 50 atomic % of the total R), and 12 to 20% R, 5 to
With a composition of 18% B, balance Fe (BH) max4MGOe
It exhibits high magnetic properties as described above. The most preferable range is from 12 to 12, with light rare earths such as Nd and Pr as the main components of R.
With a composition of 16% R, 6 to 18% B balance Fe, (BH)max is 7MGOe or more, and properties unprecedented in isotropic permanent magnet materials can be obtained. M is preferably within the same range as in the case of anisotropy except for the following. (V10.5%, W8.8% or less). When any M component is isotropic, Br shows a decreasing tendency as the amount added increases, and Br3KG or more (to be equal to or higher than the level of (BH)max2MGOe of isotropic hard ferrite) is within this range. Indicated by Binders and lubricants are generally not used in the case of anisotropic magnets because they interfere with the orientation during molding, but in the case of isotropic magnets, by including binders and lubricants, It is possible to improve the press efficiency and increase the strength of the molded product. In the case of isotropy, in addition to R, B, M, Fe, and Co, C, P, S, and Cu can also be contained within a specified range, such as C4.0% or less, P3.3% or less, and S2. .5% or less,
A range of Cu3.3% or less (however, the total of these is less than the maximum value of each component) is useful from the standpoint of improving manufacturability, etc. Furthermore, the content of Ca, Mg, O, and Si is allowed, and Ca , Mg, each 4.0% or less, and Si 5% or less (the total amount of these is 5% or less) is practically preferable. Note that the presence of other impurities that are unavoidable in industrial production can be tolerated, as in the case of anisotropic materials. As detailed above, the method for manufacturing the permanent magnet material of the present invention has excellent magnetic properties with high coercive force and high energy product of the novel FeCoBRM system, and as R
By using light rare earth elements such as Nd and Pr, it is possible to easily produce permanent magnet materials that are excellent in terms of resources and cost, and have high industrial applicability. In particular, by substituting a part of Fe with Co, it is possible to obtain a crystal with a more practical Curie temperature, and by incorporating a certain element M and subjecting it to a certain aging treatment, it is possible to obtain a crystal with a more practical Curie temperature. quality
This material achieves further improvements in coercive force and squareness of the demagnetization curve for FeBR-based or FeCoBRM-based permanent magnet materials. The aspects and effects of the present invention will be further explained below with reference to Examples. However, the present invention is not limited to the examples and described aspects. Tables 1 to 4 show various results depending on the following steps.
A permanent magnet material consisting of FeCoBRM composition was fabricated. (1) The starting materials are electrolytic iron with a purity of 99.9% (weight%, the same applies to raw material purity below) as Fe, and feroboron alloy (19.38% B, 5.32% Al, 0.74% B) as B.
%Si, 0.03%C, balance Fe), purity 99% as R
The above (impurities are mainly other rare earth metals) are used. Electrolytic Co with a Co purity of 99.9% was used. M is Ta with a purity of 99%, W with a purity of 98%, Al with a purity of 99.9%,
Fluorovanadium containing 81.2% V was used as V, ferronniobium containing 67.6% Nb was used as Nb, and ferrochrome containing 61.9% Cr was used as Cr. (2) Magnet raw materials were melted using high-frequency induction. At that time, an aluminum crucible was used as the crucible, and an ingot cast into a water-cooled copper mold was used. (3) Crush the ingot obtained by melting.
After making the powder into 35 mesh, it was further pulverized using a ball mill to obtain a predetermined average particle size. (4) The powder was molded under a predetermined pressure in a magnetic field (however, when manufacturing an isotropic magnet material, molding was performed without applying a magnetic field). (5) The compact was sintered in a predetermined atmosphere within the range of 900 to 1200°C, and then subjected to a predetermined heat treatment. Example 1 Atomic percentage composition 61Fe・14Co・7B・16Nd・
After pressing 2Mo alloy powder with an average particle size of 5 μm in a 10KOe magnetic field at a pressure of 1.5Ton/ ^cm2 , it becomes 99.99
Sintered at 1100℃ for 2 hours in 200TorrAr with % purity,
After sintering, it was cooled to room temperature at a cooling rate of 700°C/min. Furthermore, aging treatment was performed at 650℃ for 20 minutes, 120 minutes, and 240 minutes.
The magnet material according to the manufacturing method of the present invention was obtained by carrying out the experiment for 3,000 minutes. The magnet characteristic results and the temperature coefficient α (%/°C) of the residual magnetic flux density (Br) of this alloy magnet are shown in Table 1 together with a comparative example (after sintering).

[Table] Example 2 Atomic percentage composition 55Fe・150Co・12B・14Nd・
After pressing 2Y/2Nd alloy powder with an average particle size of 3μm in a 15bOe magnetic field at a pressure of 1.0Ton/ ^cm2 ,
Sintering was performed at 1180°C for 2 hours in 500 TorrAr with a purity of 99.999%, and after sintering, the material was cooled to room temperature at a cooling rate of 450°C/min. Furthermore, aging treatment was performed in a vacuum of 2×10 ⁻⁵ Torr at each temperature shown in Table 2 for 3 hours to obtain a magnet material according to the production method of the present invention. The magnet characteristic results and the temperature coefficient α (%/°C) of the residual magnetic flux density (Br) are shown in Table 2 together with comparative examples (after sintering, etc.).

【table】

[Table] Example 3 FeCoBRM alloy powder having an average particle size of 2 to 15 μm and the atomic percentage composition shown in Table 3 was prepared in a 10 kOe magnetic field.
After pressure molding at a pressure of 1.8Ton/cm ² , it was sintered at 1080°C for 2 hours in 250TorrAr with a purity of 99.999%, and after sintering, it was rapidly cooled to room temperature at a cooling rate of 700°C/min. Furthermore, aging treatment is performed for 700 hours in Ar of 600 Torr.
C. for 4 hours to obtain a magnet material according to the manufacturing method of the present invention. The magnetic properties and the temperature coefficient α (%/°C) of Br are shown in Table 3 along with a comparative example that does not contain Co.

[Table] Example 4 FeCoBRM alloy powder having the following atomic percentage composition and having an average particle size of 1 to 10 μm was heated at 1.0 Ton/min in a non-magnetic field.
After pressure molding with a pressure of ^cm2 , 99.9% purity
Sintering was performed at 1020°C for 1 hour in 150TorrAr, and after sintering, the material was rapidly cooled to room temperature at a cooling rate of 550°C/min.
Further, aging treatment was performed at 600° C. for 4 hours in 650 TorrAr to obtain a magnet material according to the manufacturing method of the present invention. The results of the magnetic properties are shown in Table 4 together with the sample after sintering without aging treatment (comparative example).

【table】

Claims (1)

[Claims] 1. 8 to 30% R (wherein R is at least one rare earth element including Y), 2 to 28% in atomic percentage
of B, one or more of the additive elements M in a specified percentage or less (excluding M0%, M is V9.5% or less, Nb12.5% or less, Ta10.5% or less, Mo9.5% or less, W is 9.5% or less, Cr is 8.5% or less, and Al is 9.5% or less, and if two or more types of M are included, the total M content is less than or equal to the specified % of the maximum value of each M element contained. ), and of the FeBRM system composition where the remainder is essentially Fe, a portion of the Fe is replaced by Co, which accounts for less than 50% of the total composition.
(excluding 0%) and has a FeCoBRM system composition and is sintered at 900 to 1200℃.
A method for producing a permanent magnet material, characterized in that heat treatment is performed at a temperature of not less than 0.degree. C. and not more than the sintering temperature. 2. The method of manufacturing a permanent magnet material according to claim 1, wherein the sintered body is obtained by molding and sintering an alloy powder composition having the FeCoBRM composition and having an average particle size of 0.3 to 80 μm. 3 8 to 30% R in atomic percentage (however, R is at least one rare earth element including Y), 2 to 28%
of B, one or more types of additive elements M at a specified percentage or less (excluding M0%, M is V9.5% or less, Mb12.5% or less, Ta10.5% or less, Mo9.5% or less, W is 9.5% or less, Cr is 8.5% or less, and Al is 9.5% or less, and if two or more types of M are included, the total M content is less than or equal to the specified % of the maximum value of each M element contained. ), one or more types of element When there are two or more types, the combined amount of X is the maximum specified percentage of each element.
(not more than the specified percentage), and a FeCoBRM composition in which part of the Fe is replaced with 50% or less of Co (excluding 0%) in the entire composition of the FeBRM composition in which the remainder substantially consists of Fe. 900~1200
A method for producing a permanent magnet material, which comprises heat-treating a sintered body obtained by sintering at ℃ at a temperature of 350℃ or higher and lower than the sintering temperature.